Vibration damper for an electric trolling motor

ABSTRACT

The invention is an accessory vibration damper that is applied over the diameter of any submersible electric motor housing of any modern electric trolling motor. Vibration damper is molded as a single unitary piece of an elastomeric compound that can have plural appendages placed perpependicular to the rotating armature of motor. Said appendages counteract the frequency range of vibrations produced while electric trolling motor is under propulsion.

THE FIELD OF THE INVENTION

The present invention is an accessory device used for dampeningvibrations created by an electric trolling motor to help improve theanglers chances of catching more fish.

BACKGROUND OF INVENTION

It has been observed by countless fishermen, that the slight noisegenerated by an electric trolling motor under propulsion can spook bassoff their beds. Modern fishing tackle includes crankbaits and buzzbaitswhich use vibrations to attract the game fish. These vibrations asslight as they are alert the fish to the bait, but can be canceled outby an electric trolling motors vibrations. Thus making the bait muchless effective and reducing the chances for catching fish.

DISCUSSION OF PRIOR ART

Person skilled in the art would be aware of many techniques that can beemployed to dampen vibration and reduce sound. Therefore it would beunderstood that an electric trolling motor rotating an impeller at anyload would-be a source of vibration and sound at certain frequencies ina body of water within a general fishing proximity. The followingpatents are a small representation of the various methods taught todampen vibrations in vibration sensitive equipment, engines,transmissions, shafts, and impellers. Most of these designs employee theuse of some form or shape of an elastomeric material to modify thevibrations set up in the systems and situations described herein asfollows:

U.S. Pat. No. 7,293,755 Miyahara, et al. 2007. A vibration isolationdevice comprising a first member for attachment to a vibratory sourceand a second member for attachment to a support body on which avibratory source is to be mounted and an elastic member interconnectingthe first attachment member and the second attachment member.

U.S. Pat. No. 7,267,318 Kennard, IV 2007. A vibration control device toreduce the effects of vibrations on vibration sensitive equipment wheresaid device is a unitary piece of a soft, pliable substance having ahardened round crown portion and in operative contact between supportsurface and equipment.

U.S. Pat. No. 7,243,895 Saito 2007. A damping and mounting structure fora motor where the use of an elastic material for vibration damping istaught.

U.S. Pat. No. 7,175,150 Chi 2007. A compound vibration damper assemblyconsisting of vertical and horizontal damping units working-together todampen vibration forces in X-, Y-, and Z-directions that teaches the useof elastomers in the base and top plates of said assembly.

U.S. Pat. No. 6,024,615 Eichinger 2000. A vibration damping system thatincorporates an inertia mass that is disposed inside the portion of arotating tubular shaft of an impeller. The mass is attached for rotationby three or more elastomeric members that attach to the inside surfaceof the rotatable shaft.

U.S. Pat. No. 5,975,972 Wilmsen 1999. The invention is a vibrationdamper having a housing formed by a shell part and a base part wherein apressure cavity is located and partially delimited by a membrane made ofan elastomer material. Enclosed within the membrane is a dome-shapedplate made of spring steel and attached to a pin that passes through themembrane and protrudes through the housing to the outside.

U.S. Pat. No. 4,884,666 Stahl 1989. The use of a torsional damper andmounting adapter is taught as a way dampen shaft vibrations and soundwhen a pair of shafts are coupled at the ends.

U.S. Pat. No. 5,231,893 Sisco et al 1993. The device is taught as a dualmode damper used to reduce crankshaft vibrations. An elastomer member isplaced between a hub and a annular inertia member. The hub is configuredto mate to the accessory drive end of the crankshaft to reducecrankshaft bending vibrations.

U.S. Pat. No. 4,905,956 Zemlicka et al 1990. Discloses a fluid mountingsystem for a marine engine. The mounting system is a combination of asolid elastomer and a fluid dampening means by which to greatly improvevibration isolation and cushioning under normal shock loads.

U.S. Pat. No. 4,200,004 Bremer 1980. Discloses a zero slip torsionalvibration damper consisting of an inertia ring coupled to a hub by meansof an elastomer member. The hub is then coupled to a shaft subject totorsional vibrations. The outer most portion of the elastomer carriesangular spaced pockets into which a damper liquid is placed to dampentorsional vibrations.

U.S. Pat. No. 5,095,786 Bellinghausen et al 1992. Teaches a method bywhich brake lathe vibrations can be dampened during turning of stock.

U.S. Pat. No. 4,962,677 Withers 1990. Discloses a torsional vibrationdamper used to dampen harmonic vibration frequencies set up in thecrankshaft of a reciprocating internal combustion engine. Deviceconsists of a hub capable of being mounted to a crankshaft and a ring ofelastomeric material placed over diameter of hub and an inertia ringpress fitted over elastomeric ring.

U.S. Pat. No. 4,044,628 Jacks 1977. Discloses a torsional vibrationdamper to reduce vibrations set up in a shaft under power. The damper isformed as an integral unit by casting it from a metal such as cast ironin a disc like shape with spiral slots. The disc has three concentriczones; an inner central zone, an outer annular zone, and an intermediatespring zone. The spring zone is the area consisting of the spiral slotshaving a predetermined size and shape to provide the desired dampingeffect and extending axially through the disc and radially between theinner and outer zones to provide spirally arranged overlapping webbedportions which act as torsional springs or shock absorbers due toinherent resiliency.

Vibration damping of certain rotating systems can be constrained due tothe requirements, the environment, and spacial restrictions that wouldprevent the use of known vibration damping means. Therefore it would besignificantly beneficial if by which a means to dampen the vibrationsand sound generated by an electric trolling motor could be provided thatwould not increase the internal dimensions of said motor or increase thepower of said motor to make up for losses caused by extra mass of aharmonic balancer.

SUMMARY OF THE INVENTION

In one preferred embodiment of the present invention the vibrationdamping device is molded out of a soft, flexible thermoplastic elastomerwith a central hub that can stretch to fit the outside diameter of anymodern electric trolling motor housing. From this central hub extend twoor more appendages outwardly with integral masses at the distal end toprovide the desired vibration and sound damping. The form and shape ofany preferred embodiment of the invention described herein could alsolend itself to other dynamic and static attachments to a vibrationexcited surface or media to reduce vibration and sound.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows-the vibration damping device (01) as described in Claim 1.

FIG. 2 shows vibration damping device (01) mounted over the outsidediameter of submersible electric motor (12) at the lower half ofelectric trolling motor assembly (20).

FIG. 3 shows a preferred embodiment of dampening device (01) asdescribed in Claim 8.

FIG. 4 shows complete electric trolling motor assembly (20) with apreferred embodiment of vibration damping device (01) installed over theoutside diameter of submersible electric motor (12).

FIG. 5 shows another preferred embodiment of dampening device (01) asdescribed in Claim 9.

FIG. 6 shows complete electric trolling motor assembly (20) with anotherpreferred embodiment of vibration damping device (01) installed over theoutside diameter of submersible electric motor (12).

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric-view of vibration damping device (01) with insidediameter of cylindrical hub (02) to receive onto the outside diameter ofsubmersible electric motor (12) and with two appendages (03) spacedaround the circumference of vibration damping device (01). FIG. 2 is anisometric view from as seen from top-left of lower half of electrictrolling motor assembly (20) showing vibration damper (01) placed overoutside diameter of submersible electric motor (12). Also shown is thepropeller (11) mounted on the output shaft of submersible electric motor(12), and support tube (13) affixed to housing of submersible electricmotor (12) which is used to mount electric trolling motor assembly (20)to the side of a boat.

FIG. 3 is a top view of a preferred embodiment of the vibration dampingdevice (01) showing four integral masses (04) at the distal ends ofappendages (03) extending away from outer diameter of vibration dampingdevice (01) and the inside diameter cylindrical hub (02) to receive ontooutside diameter of submersible electric motor (12).

FIG. 4 is an isometric view as seen from the top-left of completeelectric trolling motor assembly (20) showing a preferred embodiment ofvibration damping device (01) installed over the outer diameter of thesubmersible electric motor (12) and held in place by the friction causedby the diameter differential between the inside diameter of cylindricalhub (02) of the vibration damping device (01) and the outside diameterof the submersible electric motor (12). Also shown is the propeller(11), support tube (13), and the variable speed control (14) of electrictrolling motor assembly (20).

FIG. 5 is an isometric view of another preferred embodiment of thevibration damping device (01) as seen from the top showing the pluralappendages (03) that connect the inner diameter of cylindrical hub (02)of the vibration damping device (01) to the continuous peripheral mass(05).

FIG. 6 is an isometric view as seen from the top-right of completeelectric trolling motor assembly (20) showing another preferredembodiment of the vibration damper (01) installed over the outerdiameter of the submersible electric motor (12). Also shown is thesupport tube (13) which connects the submersible electric motor (12) tothe variable speed control (14) of the electric trolling motor assembly(20).

SPECIFICATION OF THE INVENTION

The device discussed in the following Utility Patent is a novelinvention that will help mostly bass and pan fish anglers who useelectric trolling motors for maneuvering around in fish habitat. It hasbeen observed that electric trolling motors have spooked bass off oftheir beds and have taught bass that have been caught and releasednumerous times to not go after lures or bait when an electric trollingmotor is in use. The device is a vibration damper that can be installedover the outside diameter of an electric trolling motor to reducevibration and noise resulting in more chances to catch fish. The devicewill be molded as a singular unit of a soft thermoplastic elastomerwhich will have a selected hardness for the best vibration dampingqualities. As the device is somewhat elastic it can easily be stretchedover the propeller and electric trolling motor housing and hold in placeon its own. Device can have two or more appendages around thecircumference, with or without a perimeter mass or masses to modifyvibration frequencies and reduce sound generated by the electrictrolling motor while under power.

1.) A device (01) used to dampen vibrations and sound generated by thepropulsion of an electric trolling motor assembly (20) comprising of: aflexible thermoplastic elastomer compound; molded as a single unit; acylindrical hub (02) with an inner diameter opening through center axis;two or more appendages (03) extending out from cylindrical hub (02). 2.)The device (01) from claim 1 in which flexible thermoplastic elastomercompound is in the hardness range of 30 Shore OO to 80 Shore A. 3.) Thedevice (01) from claim 1 in which cylindrical hub (02) can stretch itsdiameter as much as five times. 4.) The device (01) from claim 1 inwhich the inside diameter of cylindrical hub (02) is received ontooutside diameter of submersible electric trolling motor housing (12) andheld by friction due to constrictive forces caused by the diameterdifferential. 5.) The device (01) from claim 1 in which appendages (03)can be non-uniform in length. 6.) The device (01) from claim 1 in whichappendages (03) can be non-uniform in thickness. 7.) The device (01)from claim 1 in which the appendages (03) can be spaced randomly aroundcircumference of cylindrical hub (02). 8.) A damping device (01) used toreduce the vibrations and sound generated by an electric trolling motorassembly (20) under propulsion comprising: a thermoplastic elastomer;homogeneous throughout; a cylindrical hub (02) with inner diameter sizedto receive submersible electric trolling motor housing (12); with two ormore appendages (03) extending out from cylindrical hub; with integralmasses (04) at distal end of appendages (03). 9.) An electric trollingmotor assembly (20) in combination with accessory damping device (01)installed over the outside diameter of submersible electric motorhousing (12) comprising the following: a singular molded unit of anelastomer material; with a hollow cylindrical hub (02); with two or moreappendages (03) extending out from cylindrical hub; with a continuousperipheral mass (05) connecting distal ends of appendages (03); tomodify the vibration frequencies generated by the rotating armature ofthe submersible electric motor (12).